Already have solar?
Add a battery to it.
We add Tesla and Sigenergy batteries to existing solar systems, whoever installed them.
Use more of the energy you already generate.
Without a battery, whatever your panels make while you are out goes to the grid for a small export payment. A battery keeps it for the evening, when you would otherwise be buying electricity at the full rate.
- Charge on cheap overnight rates on a time-of-use tariff, useful in winter when your panels make less.
- Optional backup so the lights stay on in a power cut, with a backup gateway fitted.
From your existing system to stored energy.
Tell us about your system
Your address and a few details about your panels and inverter. Photos of the inverter and your MCS certificate help, if you have them.
Design
We confirm how a battery will connect to your system and which one suits your home, your energy use and your tariff.
Installation
Our team fits the battery and any backup gateway, and handles the paperwork with your network operator.
Handover
Your certificates and a walk-through of your battery and app.
We look at your system before we recommend anything.
Every existing system is different. These are the things that decide which battery suits yours and how it connects.
Your inverter
Its type and age decide how a battery connects, and whether it makes sense to replace it at the same time.
Your export arrangement
If you are paid for exporting, or still on the Feed-in Tariff, we check how a battery fits with that before you commit.
Your supply and space
Your consumer unit, your connection to the grid, and where the battery will sit, indoors or out.
Two batteries that work with existing solar.
Both can be added alongside most existing systems. Which one suits you depends on your inverter, your energy use and your plans.
Questions from solar owners.
Does it matter who installed my solar?
No. We add batteries to systems we installed and to systems fitted by other companies. We check the existing equipment first and tell you if anything needs changing.
Will a battery work with my inverter?
In most cases, yes. Both Powerwall 3 and SigenStor can be added alongside an existing system. We confirm the right setup for your inverter before you commit, and tell you if replacing it would make more sense.
I'm on the Feed-in Tariff. Can I still add a battery?
Usually, yes. Your Feed-in Tariff supplier needs to be told, and the battery has to be connected so it does not affect your generation meter. We check your arrangement and explain what it means for your payments before you commit.
Does my network operator need to know?
Yes. Your network operator has to be told about a battery, and in many cases has to approve it before it is installed. We make the application and handle the paperwork for you.
Is there VAT on adding a battery?
No. Batteries and solar panels installed in homes in Great Britain carry 0% VAT until 31 March 2027, when the rate is due to return to 5%, and that includes adding a battery to an existing system.
Where does the battery go?
Garages, utility rooms, plant cupboards and external walls are all common: both platforms are weather-rated for indoor or outdoor installation. We agree the position with you at design stage.
Read the guide.
Adding a battery to solar you already have
How a battery joins an existing system, what we check first, and what it means for the Feed-in Tariff, paperwork and VAT.
5 min read Grid & PaperworkG98 and G99 explained, in plain English
What decides G98 or G99, what an export limit really does, and how long the network operator takes to answer.
5 min read Battery StorageSolar and batteries in winter: what to expect
Less sun, same savings logic: what changes in winter, why a battery keeps earning, and how to make the most of the darker months.
5 min readFind out what a battery adds to your solar.
Tell us about your system and we will design the right battery for it, free and with no obligation.
Start my home energy design